显然, 如果存在两个奇数的话,就一定出现不了回文
然后,如果只有一个或者没有的话,动手画画,就会发现,是gcd了叭,真心不知道咋讲(
#include <set>
#include <map>
#include <queue>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int N = 2e5 + 10;
int x[N];
int main() {
int n;
cin >> n;
int sum = 0;
for(int i = 1; i <= n; i++) {
cin >> x[i];
sum += x[i];
}
if(n != 1) {
int ji = 0;
int flag = true;
for(int i = 1; i <= n; i++) {
if(x[i] % 2 == 1)
ji++;
}
int s = x[1];
for(int i = 2; i <= n; i++) {
s = __gcd(s,x[i]);
}
if(ji >= 2) {
cout << 0 << endl;
} else {
cout << s << endl;
}
} else {
cout << x[1] << endl;
}
return 0;
}